Description:A thick layer of smog continued to blanket Beijing on Monday (January 14), after the city saw the "worst on record" air quality over the weekend. Data posted on Sunday (January 13) by China's monitoring centre showed particulate matter measuring less than 2.5 micrometres in diameter had reached more than 600 micrograms per square metre at some monitoring stations in Beijing. Records show as high as 900 micrograms per square metre on Saturday (January 12) evening.(0:32)